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Steam Hammer.

97

are cut off of proper length to form the rivet, and being heated, are
dropped into the hole at b. The hammer h is now worked from
the footboard/ the blow being delivered by pressing the foot down-
ward on the latter, while
the return of the hammer
is ensured by the elasti-
city of the sapling of ash
s, which is bent on each
down stroke of the foot-
board, and in becoming
straight again lifts the
hammer. The correct
form of the rivet head
is given by applying the
cupping tool <r, held in
the hand. When the
rivet is finished it may £/LCf. «V.y.
be released and thrown
out by striking the foot
sharply on the lever /,
which thus takes the
dotted position, and the
rivet can be then picked
up and cooled in water.
i Steam Hammer
for Smithy. — Lastly,
the smith requires for
his heavy forgings the
aid of a small steam
hammer. We say* small'
to distinguish from the
larger type in use by the
forgeman,but the smith's

hammer is anything but small The one illustrated in Fig.
Plate IL, is spoken of as a 10 cwt steam hammer, and this means
that the piston and piston rod A A, the tup B, and the pallett c,
together weigh 10 cwts. This, of course, does not take account
of the steam pressure, which at 40 lbs« per square inch con-

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